Tile carpet

ABSTRACT

A carpet of a type to be used in such manner that square plate-like members having a predetermined size are laid over the floor, and more particularly, a tile carpet comprising a carpet body, a carpet base to which the carpet body is fixed, and a layer of non-hardening type adhesive arranged on the rear surface of the carpet base, characterized in that the non-hardening type adhesive layer of the tile carpet consists of a mixture of acrylic foaming resin and urethane resin hardening type adhesive and a ratio of mixing of urethane resin hardening type adhesive in the mixture is 10 to 30 weight %.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a tile carpet, which is to be laid or put on over the surface of a floor covered with many long wood strips engaging with one another without gaps, a floor finished at the surface with mortar, a floor fully covered with plastic plates, or a floor formed with fully laid plates of natural stones, or the like. The tile carpet may be merely put on, so that it does not tend to have slip between the tile carpet and the floor surface, and the tile carpet when removed does almost not have marks of an adhesive on the floor surface.

An adhesive of hardening type is in the state of liquid having fluidity when in use for adhering tile carpets on the floor and is capable of being readily contacting with an object to be adhered and of wetting it. Then, the adhesive changes into solid through heating and/or chemical reaction, so that it shows a strong connection at the interface and an effect of resisting peeling off. That is, the hardening type adhesive does, in the liquid state, wet that object to be adhered and show resistance against the peel-off in the solid state. Meanwhile, non-hardening type adhesive is a gelled soft solid when in use for adhering tile carpets on the floor. The non-hardening type adhesive can be applied, in the state of gelled soft solid, to an object to be adhered, and thereafter does not change the state but shows resistance against the peel-off. As seen, the non-hardening type adhesive when in use for adhering tile carpets on the floor shows immediately an adhering effect enough for practical use.

The tile carpet is a kind of carpet. A plurality of pieces of tile carpets is put on over a floor to form the floor surface. In comparison with carpets of standard sizes as a three-tatami-mat Japanese room type (approximately 1.7 m×2.6 m), a four-and-a-half-tatami-mat Japanese room type (approx. 2.6 m×2.6 m), etc., the tile carpet is convenient for adjusting sizes, amending partially, preserving, or other aspects. Besides, the tile carpet has apparent difference in price from order-made carpets. Moreover, the tile carpet is favorable for offerers who offer carpets since to manufacture, sell and preserve (stock) tile carpets in a single size is enough for the offerers. And it is favorable that there is not limitation regarding thickness and hardness in the aspect of keeping carpets in rolled-up state, so that tile carpet can be designed freely.

2. Prior Art

Tile carpet's basic unit is a square (500 mm per side is a most prevailing size in Japan). Tile carpets are laid without gaps over the floor and may be adjusted by cutting them into a narrow strip for a peripheral part of the floor onto which standard pieces of tile carpet having normal size and shape as they are cannot be applied. Sizes of tile carpet may be large ones such as 900 mm, 1000 mm per side other than 500 mm per side as well as smaller ones such as 450 mm, or 400 mm per side, and so on. These may be laid basically in the same manner.

In the recent time, generally, tile carpets are not provided at the rear surface with a layer of hardening type adhesive, but provided with rubber or non-hardening type adhesive applied and merely laid on the floor to thereby be regarded as completion of installation. This manufacturing and laying manners may be suitable for tile carpets which may be used as laid over the floor surface, for example, in winter but is basically removed in other seasons. Also, even the case not making repetition of laying over and removing the tile carpets, since it is not strong bonding using the hardening type adhesive, it is quite suitable for such case that any single piece of tile carpets laid over the floor is notably stained or broken to be replaced with a new piece of tile carpet. When the hardening type adhesive has been applied, working of amending by replacing only one piece of tile carpet is hard to be carried out. There is not shown one of advantages obtainable from tile carpets.

However, practically, when tile carpets laid over the floor in autumn are removed in the next spring, marks of the non-hardening adhesive are left on the floor, leading to troubles of removing the marks, and occasionally the marks cannot at all be removed.

Also, when tile carpets which had been laid over the floor last autumn are newly laid over, it is found to have lost slip resistance. A small foreign force such as walking motion causes the tile carpets to slip and be shifted in position easily, leading to poor appearance and further presumably problems of security and safety and those related to Product Liability Act (Act No. 85 of 1994).

The conventional tile carpet (of such type not provided at the rear surface with a layer of hardening type adhesive but having rubber applied or having non-hardening type adhesive applied, and being regarded as completion of installation by being merely put on the floor) employs an exfoliation paper for covering non-hardening type adhesive region. Here, it should be very much rational economically and in respect of troublesomeness if the exfoliation paper is dispensable and not employed. Regarding this point, for example, the invention disclosed in Japanese Unexamined Patent Application 2013-118913 includes such proposal of adhesive applying method that surfaces each having non-hardening type adhesive applied (and exposed) thereon are put together with the adhesive on each surface being not overlapped. However, the adhesive applying method still has not reached a fundamental solution.

Under the circumstances, waited for has been such tile carpet having all of required functions that no marks remain after peeling off the carpet, slip resistance can be kept even when peel-off is repeated, and there is no need to employ an exfoliation paper.

SUMMARY OF THE INVENTION

The inventor zealously studied the above-mentioned problems and achieved the present invention which is a carpet of a type to be used in such manner that square plate-like members having a predetermined size are laid over the floor, and more particularly, a tile carpet comprising a carpet body, a carpet base to which the carpet body is fixed, and a layer of non-hardening type adhesive arranged on the rear surface of the carpet base, characterized in that the non-hardening type adhesive layer of the tile carpet consists of a mixture of acrylic foaming resin and urethane resin hardening type adhesive and a ratio of mixing of urethane resin hardening type adhesive in the mixture is 10 to 30 weight %.

DETAILED DESCRIPTION OF THE INVENTION

When urethane resin hardening type adhesive is continuously mixed with acrylic foaming resin, there causes slip resistance at a certain point of mixing and “stickiness” becomes high when mixing exceeds another point. The non-hardening type adhesive's function of putting together is inherently from or depends upon this “stickiness”. The present invention limits the “stickiness” to a state suitable for tile carpets and has achieved a well balance of the facts that no marks remain when tile carpets are peeled off and slip resistance can be kept even when peel off is repeated. A mixing ratio 10 to 30 weight % of urethane resin hardening type adhesive in the mixture of acrylic foaming resin and urethane resin hardening type adhesive is the composition and ratio just worked out by the inventor.

Meanwhile, the non-hardening type adhesive in the present invention makes foaming. The invention does not limit an expansion ratio of foaming since an optimum value is different depending upon what a carpet base is or upon which the floor (on which the carpet is put) is a wooden floor or a mortar floor. In the range of test made by the inventor, an expansion ratio of approximately 1.5 to 2.5 times was preferable.

A quantity of applying of non-hardening type adhesive varies depending upon specific conditions. In detail, non-hardening adhesive less spreads through the carpet base such as polyvinyl chloride, so that a smaller amount of the non-hardening type adhesive shows its function. Otherwise, the non-hardening type adhesive much spreads through the carpet base, for example, felt, etc., whereby the required amount of the non-hardening type adhesive increases.

Methods for applying non-hardening type adhesive are not at all limited. Any methods will do, for example, whole surface applying, screen printing, or, arrangement of projecting lines of adhesive according to such coating method that a plate-like member having at its lower end cuts formed at suitable intervals pushes a carpet base to move forward the carpet base with non-hardening type adhesive being fed to the rear side of the plate-like member.

The present invention is quite high grade and has the following advantages.

-   (1) Provided proper cushioning properties according to use of     foaming resin for non-hardening type adhesive. -   (2) The layer of non-hardening type adhesive is a mixture of acrylic     foaming resin and urethane resin hardening type adhesive and a     mixing ratio of urethane resin hardening type adhesive in the     mixture is 10 to 30 weight %. Thus, there is provided low     adhesiveness. Hence, the tile carpet when peeled off after long used     will leave no marks of adhesive. And since adhesiveness is low,     manufacturing, transporting and preserving of the tile carpets are     enabled without use of the exfoliation paper. -   (3) Since adhering effect does not tend to deteriorate, the tile     carpet is suitable for repetition of use. -   (4) The tile carpet even when made as a washable type does not have     deterioration of function or efficacy of non-hardening type     adhesive, thereby becoming a product suitable for repetitive use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view showing an example of a tile carpet according to the present invention.

PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows schematically an example of a tile carpet 1 according to the present invention (called hereunder the carpet 1). As seen from the drawing, the carpet 1 consists of a carpet body 2, a carpet base 3, and a layer 4 of non-hardening type adhesive. The carpet body 2 serves to be a surface to be exposed when the carpet 1 is put on the floor, and the carpet body 2 in this example is pile made of polypropylene as a material. Other materials, such as synthetic fibers (for example, nylon given colors at a preceding initial stage), or natural fibers, will do also. The carpet base 3 employs polyvinyl chloride in this example and may be further provided with a felt layer on the rear surface. Also, a glass fiber cloth, or the like may be arranged between the carpet body 2 and the carpet base 3. These features are said to be a typical structure for this kind of carpet. To be noted is that the carpet 1 in this example is a square having an extent of 500 mm×500 mm.

In the present invention, non-hardening type adhesive forming the non-hardening adhesive layer 4 is a mixture of acrylic foaming resin and urethane resin hardening type adhesive, and a mixing ratio of urethane resin hardening type adhesive in the mixture is 10 to 30 weight % (20 weight % in this example). Foaming is made by mechanical foaming and expansion ratio of foaming is 1.5 times. The non-hardening type adhesive was applied to the carpet base 3 (polyvinyl chloride in this example) at a quantity of 10 g per carpet base with screen printing technology.

Resultantly, in our test that a single piece of the carpet was placed on a flooring surface, and a tester walked, treaded and passed there, it was clearly found that the carpet does not tend to shift in position in comparison with a conventional product of our company.

To make apparent the fact objectively, we carried out a test by use of a freely usable equipment “Lisson type abrasion testing machine” possessed by Local Independent Incorporated Administrative Agency, Technology Research Institute of Osaka Prefecture. The testing machine has been often used for testing abrasion of artificial turf. The testing machine used by the inventor was provided circumferentially with three treadmills. The treadmills were turned while walked (moved) on the object to be tested, thereby measuring abrasion.

In detail, the treadmills were rotated with load of 198N (20 kg) being applied thereto (the treadmills were simultaneously moved horizontally), so that a quantity of shift of the object to be tested (employed as a test piece was a product carpet cut into 200 mm square) was measured when the treadmills each pass the test piece, whereby obtaining numerical values of easy shifting of carpet corresponding to walking on the carpet. The numerical values were calculated by performing measurement 12 times and excluding maximum and minimum measurement values to obtain mean values regarding 10 times of measurement. And, used for the test were two types of a flooring surface, namely, a type having almost no cushioning properties (called type 1) and another type having cushioning properties (type 2). Naturally, the object to be tested which shows a smaller measurement numerical value is higher in slip resistance properties, which means that everyday movement of walkers such as moving on the carpet does not easily cause the carpet to slip.

As a result, the carpet 1 in this example showed such measurement results of shift as 2.0 mm on the type 1 and 0.2 mm on the type 2. The tests were performed also for our company's conventional products and other company's products. Resultantly, the carpet 1 according to the present invention showed almost smallest numeric values although not notable among all of these products. To be noted that other products which show almost same numerical values as of the carpet 1 all do have disadvantage as having high adhesiveness and thereby be hard to be peeled off. Hence, they do not achieve the feature related to another object of the present invention that when the carpet is peeled off after used long, no marks are left.

Furthermore, the non-hardening type adhesive shows less stickiness, and therefore, does not catch or be not adhered to by dust or fluff as different from a general non-hardening type adhesive. Regarding a tile carpet, lowering of adhering effect of non-hardening type adhesive applied on the rear surface of the tile carpet is caused mainly by that dust or fluff adhere to the surface of the non-hardening type adhesive. According to the feature of the present invention, the adhering effect or efficacy of non-hardening type adhesive is not inclined to lower.

An exfoliation paper is generally accompanied with a conventional type of tile carpet having non-hardening type adhesive. The carpet 1 of the present invention employs non-hardening type adhesive less feeling of stickiness, so that dust or fluff do not adhere to the surface of the non-hardening type adhesive. Thus, the exfoliation paper is unnecessary.

The exfoliation paper is needed in the case using a conventional type of non-hardening type adhesive and in the process of cutting raw fabric of the carpet. This is because it is necessary to prevent lowering of adhesive effect due to that dust or fluff formed upon cutting the raw fabric of carpet adheres to non-hardening type adhesive. And the exfoliation paper will be not removed even after the carpet is manufactured and functions as a protection sheet. In a general practice, the exfoliation paper is removed by an operator upon installing the carpet onto the floor surface. The operation of removing or peeling off the exfoliation paper is not so hard or troublesome, but a substantial quantity of waste will be formed and necessitate complicated and troublesome disposing process.

The present invention does not at all require the exfoliation paper from the stage of manufacturing, so that cost for the exfoliation paper is not needed, working to set exfoliation paper on the one side of carpet raw fabric is not needed upon manufacturing the carpet, and also not needed is working to peel off the exfoliation paper upon putting the carpet on the floor.

The non-hardening type adhesive layer 4 is formed by applying non-hardening type adhesive. Methods of applying the adhesive are not at all limited. In the example shown in FIG. 1, the non-hardening type adhesive was applied in such manner that with the carpet base 3 employing polyvinyl chloride, the adhesive was applied through a screen printing technology. Felt instead of polyvinyl chloride is often used for the carpet base 3. In this case, non-hardening type adhesive spreads through the carpet base (felt) and the quantity of spreading is not constant, whereby it is hard to keep the function or effect of slip resistance. For the circumstances, it is preferable, for obtaining more than a predetermined level of effect of slip resistance, to adopt a method of applying the adhesive over the whole surface, or a method of coating that a plate-like member having at its lower end cuts formed at suitable intervals pushes a carpet base to move forward the carpet base with non-hardening type adhesive being fed to the rear side of the plate-like member (with the latter method, projecting lines of adhesive are arranged on that rear side of the plate-like member). 

What we claimed is:
 1. A carpet of a type to be used in such manner that square plate-like members having a predetermined size are laid over the floor, and more particularly, a tile carpet comprising a carpet body, a carpet base to which the carpet body is fixed, and a layer of non-hardening type adhesive arranged on the rear surface of the carpet base, characterized in that the non-hardening type adhesive layer of the tile carpet consists of a mixture of acrylic foaming resin and urethane resin hardening type adhesive and a ratio of mixing of urethane resin hardening type adhesive in the mixture is 10 to 30 weight %. 